Abstract

The goal of this research is to study the reasons for the formation of rigid non-metallic inclusions in rail steel and ways to reduce the rejection of finished rails for defects in ultrasonic testing. The research was carried out at the arc-furnace plant of JSC Ural Steel. The central plant laboratory carried out a chemical analysis of non-metallic inclusions in the specimens of finished rails, rejected by ultrasonic inspection during the rail production by Aktobe Rail and Structural Steel Plant, LLC from a billet produced by Ural Steel. In terms of composition, non-metallic inclusions are represented by aluminum oxides. The most probable reasons for the presence of non-metallic inclusions are determined as a result of ferroalloys containing aluminum in their composition, or the interaction of melt components with refractories and a mold powder. The analysis of ferroalloys used in the production of rail steel is carried out. Industrial testing of the continuous rail steel casting technology is carried out with the replacement of FS65 ferrosilicon, which contains aluminum with silicon carbide. An increase in the degree of silicon and carbon recovery is noted in experimental smeltings. The assessment of contamination with non-metallic inclusions and mechanical properties of the rail steel obtained by the experimental technology shows that the service characteristics of the rail steel metal comply with the requirements of GOST R 51685–2013. The full-scale experiment has confirmed that the technology of alloying E76F rail steel with silicon carbide under conditions of Ural Steel is technically feasible. A 17% increase in the yield of useful 100-meter rails was obtained for a pilot batch of metal, produced from Ural Steel’s contcast steel billets.

中文翻译：

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以提高非金属夹杂物清洁度为目标的钢轨连铸工艺优化

摘要

本研究的目的是研究钢轨钢中刚性非金属夹杂物形成的原因，以及在超声波检测中减少成品钢轨缺陷的方法。该研究是在 JSC Ural Steel 的电弧炉工厂进行的。中央工厂实验室对成品钢轨样品中的非金属夹杂物进行了化学分析，在 Aktobe Rail and Structural Steel Plant, LLC 使用 Ural Steel 生产的钢坯生产钢轨期间，通过超声波检查不合格。在成分上，非金属夹杂物以氧化铝为代表。存在非金属夹杂物的最可能原因是铁合金成分中含有铝，或者熔体成分与耐火材料和保护渣相互作用。对用于生产轨道钢的铁合金进行了分析。用碳化硅替代含铝的 FS65 硅铁，对连续钢轨铸钢技术进行了工业测试。在实验冶炼中注意到硅和碳回收程度的增加。通过实验技术获得的轨道钢非金属夹杂物污染和力学性能评估表明，轨道钢金属的使用特性符合GOST R 51685-2013的要求。全尺寸试验证实，在乌拉尔钢条件下用碳化硅合金化E76F轨道钢的技术在技术上是可行的。